Rubber adherent wire



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w. E LEONARD RUBBER ADHERENT WIRE Filed June 18, 1943 2 Sheets-Sheet l FIE- 1- Waff/a ,9m/5; 50M/@Wina CMM/fm Fmr/N6.

Comms Us PLASTIC Oct. 23, 1945. w E. LEQNARD 2,387,335

RUBBER ADHERBNT WIRE Filed June 18, 1943 2 Sheets-Sheet 2 Patented Oct. 23, 1945 2 87, X /6 3 3 UNITED STATES PATENT OFFICE RUBBER ADHERENT WIRE William E. Leonard, Worcester, Mass., assignor to The American Steel and Wire Company of New Jersey, a corporation of New Jersey Application June 18, 1943, Serial No. 491,339

11 claims. (c1. 18-59) The present invention relates to surface treat- The alkali cleansing solution for step 1 is ing metal stock, particularly to the surface treatmade by mixing any one or both of the above ing of ferrous metal such as wire, etc., in order t alkali powders with gt''tl'simcferpromote those properties of adhesion to rubber, ll'yb'lted to a temperature of from apthis invention being a continuation-impart of the 5 proximately 180 to 2005i?.

invention disclosed and claimed in my @Opending (2) After the above alkali cleansing treatment, application Serial NO- 351,431, filed August 4, the coils of wire are washed or rinsed in Water, 1940, and entitled Rubber adherent Wire. either by dipping in a receptacle or spraying The essential steps of the present invention are water thereon, as indicated at 2 in the diagram. schematically illustrated in the accompanying (3) As indicated at 3 in Figure 1, the coils of drawings, in which: wire are next immersed in a 5% to 6% solution Figure 1 i5 a diagrammatic View illuStiatng the of sulphuric acid, where they are allowed to reseveral steps, which are numbered to correspond main for an interval of about one-half minute. to the descriptive texts hereinafter set forth in This acid bath is maintained at a temperature of greater detail. approximately 180 to 200 F. This acid etching Figure 2 is a detail view of a wipe for round step attacks or eats into the surface of the stock ferrous stock, such as wire, as it emerges from by dissolving the iron, and leaves the carbdes one of the baths of the process. in the steel in substantially their normal condi- Fig'ures 3 and 4 are detail views of a special die tion, so that as a result of this step 3, a rougharrangement through which the elongated metal ened or irregular surface is imparted to the wire stock is drawn. stock, but the interior or body of said Wire stock According to the invention, carbon steel Wire is not injuriously aected by the acid. is bright drawn to finished size in any convenient (4) Thereafter, one or more coils of Wire, upon or conventional manner. The drawn wire is genremoval from the acid etching bath of step 3, erally accumulated in batches in coiled or bun- 0 with the acid remaining thereon, are placed on died form. During the usual Wire drawing OP- H buggies where they are held in the open air and eration, the surface of the wire becomes covered thus subjected to the action of the Oxygen in the with a thin lm 0f Suap used aS a Wire drawing atmosphere. The time interval for which the lubricant. wire is subjected to the action of the atmosphere The advantageous results 0f the invention are 30 may range anywhere from five minutes to three obtainable by the practice of the following Stepsr hours. For example round wire of .006'l to .008"

(1) Each COlad bundle iS ISt given a quick diameter will be exposed to the action of the oxydp in a hot alkali solution` whose function is to gen in the atmosphere for about ve minutes, remove the above mentioned SOaIJ film and t0 whereas wire of a diameter of approximately thoroughly cleanse the surface of the wire stock 3 0172" may be exposed for approximately three PI'iOI t0 the acid atching treatment hereinaftaf hours. The described quick dip of the coiled wire referred to. A suitable alkali solution for this in the etching bath and Subsequent treatment Step can be prepared by mixing certain knOWn by exposure to atmospheric oxygen is deemed to commercially obtainable ingredients with water. be highly important, since if the Wire were a1- Ffm' eXamD1e,I mair prepare Suitable alkali S0111- 40 lowed to remain in the acid over an extended 1710115 by the use 0f either Oaklt. IO- PQFYQT Y period of time, gas due to electrochemical action sold by oaklle Produts Incorporanteaor .1i-1.91192, Of acid would make the Wire brittle, which is @legal POWueLSOld by The Houghton Company objectionable, In short, it would bring about 0f Pmladelphla- The Composition 0f Sad ,QM what is known to those skilled in the art as hy- Sodium hydroxide 23,2 were the wire immersed and held in the acid for Sodium orthosilicate ':f- 23,2 a long period of time. The described atmospheric Tri-Sodium phosphate Trace treatment is advantageous, since a satisfactorily Balance irt material including moisture, roughened or irregular surface is obtained while at the same time the wire retains its high tensile strength and ability to resist torsion.

(5) 'I'he bundles of etched Wire are then given a quick dip, for example, a half-minute immersion, in an alkali solution. A suitable solution for the purpose may be made by dissolving either Oakite No. 24 powder or Houghtons No. 127 powder of the above described compositions, in a body of water.

(6) After the bundles are removed from the alkali bath of step 5, they are then washed or rinsed with plain water, either by dipping in a tank or by spraying as suggested at step 6 in the drawings. 'I'he functions of steps 5 and 6 are to remove all traces of acid and to thoroughly cleanse the Wire stock in preparation for the subsequent step.

(7) The wire which has been roughened, treated and cleaned according to the steps previously described, is thereafter subjected to a treatment which is eiective to apply a metallic layer in such a way that the irregularities of the metal layer will be effectively -reiiected` This step, as suggested at 'l in the diagram, constitutes immersing the roughened wire in a copper sulphate solution, in the absence of an electric current, to thus chemically deposit a thin film of copper on the roughened ferrous metal base. In practice, it is found that satisfactory results may be secured by the use of either a hot or cold solution. In some cases a tin coating may be applied, but when tin is used the tin sulphate solution must be maintained at a temperature of from 160 to 180 F. In some cases a mixture of copper sulphate and tin Will be used, in which case the solution should be kept cold. The wire or other ferrous metal stock is held in either the copper or tin sulphate solutions described for a period of from two to four minutes, depending upon the diameter of the stock under treatment. In treating wire .005 to .O20 inch in diameter, it is held in the solution for approximately two minutes. In the treatment of stock of from .037 to .O72 inch in diameter, the same is held in the solution for about four minutes.

(8) Following the application of a thin layer by the chemical deposition as set forth in the preceding paragraph, the coils of wire with the thin lm of copper or tin or combination of copper and tin thereon, are then washed with cold water, as suggested in step 8 of Figure l.

(9) Following the water rinse, the coils cf wire are placed in a vat or tank containing rye meal liquor, so as .to protect the wire from corroding,

as indicated at 9 in the drawings.

(10) Following the immersion of the coils in the rye meal liquor referred to, the wire is continuously drawn between dies D, as suggested in step 10 of Figure l, these dies being so shaped as to provide an undulating pass which is eifective to reversely bend the wire and thus effectively work the plated layer on wire and also impart a. bright nish thereto, and give the wire the correct cast or set.

(11) After the wire has been subjected to the steps above enumerated, it is fed in a substantially continuous manner through an extrusion apparatus of conventional form suggested at E in Figure 1. The extrusion apparatus is adapted to apply a synthetic rubber in such a way that the rubber or equivalent layer becomes intimately interlocked with the irregularities of the copper or tin film, which irregularities, it will be remembered, reect those irregularities effected by the acid uniform layer of either natural or u etching treatment, which was augmented by the exposure of the etched wire to the atmosphere. Instead of applying rubber or synthetic rubber, I may apply suitable synthetic resins of known compositions.

Where the term rubber is used herein, it is to be understood, therefore, that I may substitute synthetic rubber or suitable synthetic resins as the equivalents of such rubber.

(12) When a rubber layer is applied by extrusion or by any other conventional rubber-applying method, the rubber coating is preferably vulcanized. This is suggested in the step numbered 12 in Figure 1 of the drawings.

After the wire leaves the bath of rye meal liquor suggested in step 9 of Figure 1, it is sometimes desirable to subject it to the action of a wipe 5 such as shown in Figure 2. This wipe consists merely of a length of carbon steel wire 8, doubled on itself and secured in any suitable manner, as by means of an eye 9, the free ends of the wipe being twisted around the Wire or rod l0 under treatment. The high carbon strand 8 is coiled or wrapped around the wire stock I0 while the latter is at rest, and is made sufficiently tight so that once the stock I 0 is set in motion, the wipe will tend to elongate somewhat under the influence of tension, thus causing the individual convolutions to yieldingly grip the moving stock. This is effective in partially removing the rye meal liquor, and also probably assists in working the copper or other metallic plating into the irregular surfaces of the stock. The working of the stock into the irregularities is made more positive, however, by the reverse bending operation by passage through the undulating pass of the dies D, as suggested in 4, made of any suitable material such as shown at 6 in Figure 3. The die block illustrated may be of two half sections of an 8"x8" timber parted along an undulating plane, as shown at il, so as to comprise complementary die sections 6e and 6b. Suitable clamps or bolts I2 are provided to hold the die sections in proper engagement with the wire during its passage therethrough. During the passage of the wire stock through the undulating pass dened by the die sections 6a and 6b, the Wire is also subjected to the finishing action of a cotton wipe I3 which is held in place by the clamping action of the die sections. The split die 6 thus simultaneously effects a thorough wiping of the wire, works the plating adhering thereto into the etched irregularities, and imparts to the wire any predetermined set which may be K desired to facilitate coiling where a straight wire is not to be produced. finished product can shape of the surface of nal form to the Wire ment.

A greatly improved product in the form of Wire with an adherent coating thereon results from the practice of the described method. This product, it will be appreciated, is in the form of an elongated rod or Wire of ferrous metal, the surface of which has been made irregular by the acid etch and exposure to air. Over the irregular surface there is a chemically deposited film of copper, the lm being of substantially uniform thickness, thus reilecting the irregularities in the plated coating. The rubber adheres better to the copper than it would to a ferrous base, and the tenacity of its adherence is augmented by the ir- 'Ihe set imparted to the be varied by varying the l I so as to give any desired 0r rod stock under treatregularities referred to. Actual reduction to practice has demonstrated the superiority of the product over copper coated in the ordinary way with a smooth coating.

While in the foregoing disclosure I have recited precise preferred steps which an actual reduction to practice on a commercial scale has shown to be highly desirable, it is not to be construed that I am limited thereto, since various modications may be made without departure from the spirit and scope of the invention as dened in the appended claims.

I claim:

1. In the treatment of ferrous metal stock to increase its rubber-adherent characteristics, the method which comprises washing the stock in an alkali solution, rinsing the stock in water to remove any adherent alkali, etching the surface of the stock in an acid bath whereby the surface thereof is rendered somewhat irregular, withdrawing the stock from the etching bath and exposing it to the action of atmospheric air for a determined time interval whereby the surface of the stock becomes more deeply etched and irregular due to the combined action of air and acid clinging to the surface, cleaning the stock with an alkali solution and water, chemically depositing a layer of metal over the irregular roughened surface of the thus treated stock whereby the irregularities effected by the prior steps are reflected in the coated stock, and then applying a body of rubber to the irregular chemically deposited metallic layer.

2. In the treatment of ferrous metal stock to increase its rubber-adherent characteristics, the method which comprises washing the stock in an alkali solution, rinsing the stock in Water to remove any adherent alkali, etching the surface of the stock in a bath 'of dilute sulphuric acid whereby the surface thereof is rendered somewhat irregular, withdrawing the stock from the etching bath and exposing it to the action of atmospheric air for a determined time interval whereby the surface of the stock becomes more deeply etched and irregular due to the combined action of air and sulphuric acid clinging to the surface, chemically depositing a layer of metal over the irregular roughened surface whereby the irregularities eiected by the prior steps are reected in the coated stock. cleaning the stock by dipping in an alkali solution and then washing with plain water, and then applying a body of rubber to the irregular chemically deposited metallic layer.

3. In the treatment of ferrous metal wire to increase its rubber-adherent characteristics, the method which comprises Washing the wire in a hot alkali solution, applying water to the wire to remove substantially all of the adherent alkali solution, etching the surface of the wire by dipping it in a bath containing approximately ve per cent of sulphuric acid maintained at a temperature from approximately 180 to 200 F., said bath being effective to etch the surface of the wire and render it somewhat irregular, withdrawing the thus etched wire from the sulphuric acid bath and exposing it to the action of atmospheric air for an interval of from five minutes to three hours, whereby the surface of the wire becomes more deeply etched and irregular due to the combined action of the air on the acid adhering to the surface, cleaning the stock with an alkali solution and water, chemically depositing, in the absence of electric current, a layer of metal on the etched stock whereby the irregularities effected by the previous steps are reflected in the coated wire, then applying a layer of rubber to the wire.

4. In the treatment of ferrous metal wire to increase its rubber-adherent characteristics, the method which comprises washing the wire in a hot alkali solution, applying water to the wire to remove substantially all of the adherent alkali solution, etching the surface of the wire by dipping it in a bath containing approximately five per cent of sulphuric acid maintained at a temperature from approximately 180 to 200 F.said bath being effective to etch the surface of the wire and render it somewhat irregular, withdrawing the thus etched wire from the sulphuric acid bath and exposing it to the action of atmospheric air for an interval of from five minutes to three hours, whereby the surface of the wire becomes deeply etched and irregular due to the combined action of the air on the acid adhering to the surface, cleaning the stock with an alkali solution and water, passing the wire through e. bath of copper sulphate solution in the absence of an electric current to chemically deposit a film of copper on the surface of the wire whereby the irregularities due to the acid etching will be reflected in the copper lm thus applied to thus increase the rubber-adherent characteristics of the wire, reversely bending the coated Wire to mechanically work the copper lm, and thereafter applying a layer of rubber to the wire.

5. In the treatment of ferrous metal wire to increase its rubber-adherent characteristics, the method which comprises washing the wire in a hot alkali solution, applying water to the wire to remove substantially all of the adherent alkali solution, etching the surface of the wire by dipping it in a bath containing approximately ve per cent of sulphuric acid maintained at a. temperature from approximately 180 to 200 F.. said bath being effective to etch the surface of the wire and render it somewhat irregular, withdrawing the thus etched wire from the surphuric acid bath and exposing it to the action of atmospheric air for an interval of from five minutes to three hours, whereby the surface of the wire becomes deeply etched and irregular due to the combined action of the air on' the acid adhering to the surface, cleaning the stock with an alkali and water solution, passing the wire through a bath of copper sulphate solution in the absence of an electric current to chemically deposit a lm of copper on the surface of the wire in such manner that the irregularities due to the etching will be reflected in the copper film thus applied to thus increase the rubber-adherent characteristics of the wire, reversely bending the coated wire to mechanically work the copper lm, and thereafter applying a layer of rubber about the thus copper-coated wire and vulcanizing the rubber layer.

6. In the treatment of ferrous metal stock to increase its rubber-adherent characteristicsy the method which comprises etching the surface of the stock in an acid bath whereby the surface thereof is rendered somewhat irregular, withdrawing the stock from the etching bath and exposing it to the action of atmospheric air for a determined time interval whereby the surface of the stock becomes more deeply etched and irregular due to the combined action of air and acid clinging to the surface. cleaning the stock with an alkali and water solution, chemically depositing a layer of copper over the irregular roughened surface whereby the irregularities effected by the prior steps are reflected in the coated stock, and then applying a body of rubber to the irregular chemically deposited metallic layer.

7. A new article of manufacture consisting of a ferrous metal Wire characterized by an etched surface, a cuprous plating reecting the irregularities of the etched surface, and an adherent rubber skin on the plated Wire and intimately interlocked therewith by virtue of such irregularites.

8. As a new article of manufacture, a ferrous metal wire characterized by an irregular outer surface, a thin lm of copper chemically united to the ferrous metal Wire and reecting the irregularities thereof, and a rubber skin vulcanized thereto and thus interlocked with the irregularities of said copper lm.

9. A new article of manufacture consisting of a ferrous metal wire characterized by a deeply etched irregular surface and a cuprous plating reflecting the deep irregularities of the etched surface, said Wire being adapted to have a skin of rubber or synthetic rubber interlocked with the deep irregularities of said cuprous plating.

10. A new article of manufacture, consisting of a ferrous metal wire characterized by a deeply etched irregular surface and a thin lm of nonferrous metal united to the metal Wire and reflecting the deep irregularities of the etched surface, said Wire being adapted to have a skin of rubber or synthetic rubber adhered to and interllrglred with the deep irregularities of said metal 11. A new article of manufacture, consisting of a metal Wire characterized by a deeply etched irregular outer surface, a thin iilm of non-ferrous metal united to the Wire and reflecting the irregularities thereof, and a rubber skin intimately interlocked therewith by virtue of such irregu- WILLIAM E. LEONARD. 

